The Energy Minister says rising power costs are because of low supply.

Heavy business users have warned spiking prices threaten their viability - including timber mills facing possible closure.

The Electricity Authority and Commerce Commission has been asked to look at whether power companies are price gouging.

The Government is also looking to import more liquefied natural gas.

Simeon Brown says the last Government's ban on gas exploration was detrimental.

"The key thing is that we have a shortage of energy - and that is what is driving this situation." 

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